The tragedy of modern Western philosophy lies, from the Muslim point of view, in confusing intellect and reason. The intellect to which the Sufi doctrine appeals and through which it is understood is that instrument of knowledge which perceives directly. It is not reason which is, at best, its mental image. Intellectus is not ratio. The latter can create and understand philosophy in the usual meaning of the word; only the former can understand metaphysics in its true sense which lies at the heart of the doctrine. To comprehend the doctrine is therefore not just to try to conform ideas to a logical pattern. Nor is it to play with ideas and seek to perform any kind of mental acrobatics. It is a contemplative vision of the nature of things made possible through intellection. The doctrine or metaphysics would be the easiest thing to teach if all men could understand as easily as they can reason. But in fact it is most difficult to explain precisely because only a few are capable of intellection. That is why even within the Tarîqah [i.e. spiritual path within Islam] only a small number are capable of fully comprehending the doctrine.

Doctrine is in a sense the beginning and end of the Path. It comes at the beginning as a knowledge that is 'theoretical' and at the end as one that is realized and lived. Between the two there is a world of difference. Every doctrinal work of Sufism is like a key with which a particular door is opened and through which the traveller must pass until finally, at the end of the road, he realizes in his being the doctrine that he knew 'theoretically' at the beginning. There are those who belittle doctrine in the name of experience. But doctrine is absolutely essential especially at the beginning of the Path when man is lost in the maze of distracting thoughts, and especially in modern times when the confusion in the mental plane makes the possession of a clear vision of the nature of things indispensable. The doctrine at the beginning is like the map of a mountain to be climbed. At the end it is the intimate knowledge of the mountain gained through the actual experience of having climbed it.

Also in the same way that different descriptions can be given of a mountain depending on the angle from which it is being viewed, doctrine is often expressed in terms that may seem contradictory in certain external aspects. But the subject of all the descriptions is the mountain and the content of all the expressions of doctrine is the Truth which each formulation expresses from a certain point of view. In metaphysical doctrines there is no innate opposition, as in schools of philosophy, but complementary forms that reveal the same essence.

All doctrine, as already stated, is essentially the distinction between the Real and the apparent, the Absolute and relative, or substance and accidents. Its cardinal teaching is that only Allah is absolutely Real and consequently this world in which man lives is contingent. Between God, who transcends Being and whose first determination is Pure Being, and this world, which is farthest away from It, there are located a number of other worlds each standing hierarchically above the other in the scale of universal existence. Together they comprise the multiple states of being, which all receive their being from God, while before Him they are literally nothing. Man thus stands before this vast number of worlds above him, and beyond them before the Divine Presence Itself which, although completely transcendent with respect to all domains of the Universe, is closer to man than his jugular vein.

The central doctrine concerning the ultimate nature of reality has usually been called wahdat al-wujûd or the (transcendent) unity of Being. This cardinal doctrine, which is not pantheism, or pan-entheism nor natural mysticism as Western orientalists have called it, is the direct consequence of the Shahâdah. It asserts that there cannot be two completely independent orders of reality or being which would be sheer polytheism or shirk. Therefore, to the extent that anything has being it cannot be other than the Absolute Being. The Shahâdah in fact begins with the lâ, or negation, in order to absolve Reality of all otherness and multiplicity. The relation between God and the order of existence is not just a logical one in which if one thing is equal to another the other is equal to the first. Through that mystery that lies in the heart of creation itself, everything is, in essence, identified with God while God infinitely transcends everything. To understand this doctrine intellectually is to possess contemplative [intuitive] intelligence; to realize it fully is to be a saint who alone sees 'God everywhere'.